Light-Permeable Roof Element for Motor Vehicles

ABSTRACT

A roof element  1  which is designed to close an opening which is made in the roof of a motor vehicle having a translucent pane which is to be permanently connected to the contact surface which borders the roof opening, especially for a contact surface originally designed to receive a sheet metal panel instead of a glass pane roof element. The roof element has at least one transition element which is joined permanently to the inner peripheral surface of the pane, and has a support surface which is parallel to the part of the contact surface on which the indicated support surface is to be superimposed.

This invention relates to a translucent roof element which is designedto close an opening made in the roof of a motor vehicle.

It is prior art that the roof of a motor vehicle can be formed at leastpartially by a transparent or translucent pane, especially of glass orplastic material. In the known manner the opening made in the roof isbordered by a stop which forms a contact surface and a terminatingsurface which is designed to hold the peripheral edge of the glass pane.

Generally the opening extends in the transverse direction between theside boundary lines of the body and in the lengthwise direction betweenthe front roof element which separates the inside roof lining and thewindshield, and the rear roof element which separates the inside rooflining and the rear window or rear hatch. The side roof elements, thefront roof element and the rear roof element each have a separateperipheral stop on their edge which is located opposite the opening. Thecombination of these four individual peripheral stops forms the contactsurface which makes it possible to hold the peripheral edge of the glasspane, permanent connection of which takes place in the known manner bycementing.

In practice, a motor vehicle with a glass roof is simply a derivative ofa traditional model with a sheet metal roof. This means that the glasspane must be cemented onto a standard body, i.e. therefore onto acontact surface which is not specifically designed for this purpose.Since at this point this contact surface in the form of a stop isdesigned fundamentally for welding on a sheet metal roof, it need notmeet any special requirements with respect to flatness or continuity.This is a major disadvantage in the case of cementing on a glass pane.

The technique of permanent joining by cementing requires a regular,continuous contact surface which runs essentially parallel to theelement which is to be permanently joined. If there are defects offlatness and/or if there are interruptions, it is such that theregularity and continuity of application of the cement are no longerensured. This results in a major risk of leaks once the pane has beenattached. If this defect is to be remedied and/or the distance betweenthe contact surface and the surface of the element to be connected hasmajor deviations, there can be an attempt to apply additional cement.Unfortunately it is well known in the technical field of cementing thatan excess of cement cannot be absolutely linked to good attachment.

Accordingly the object of this invention is to propose a roof elementwhich is designed to close an opening which has been made in the roof ofthe motor vehicle and which has a translucent pane which is suited to bepermanently joined to the contact surface which borders the opening, andthe indicated roof element would make it possible to avoid the problemsaccording to the prior art by enabling efficient cementing regardless ofthe profile of the contact surface and at the same time guaranteeingincreased tightness of the connection which has been made in this way.

This object is achieved as claimed in the invention in that the roofelement moreover has at least one transition element which is attachedpermanently to the inner peripheral surface of the pane and which has asupport surface which is essentially parallel to the part of the contactsurface on which the indicated support surface is superimposed.

Each transition element is accordingly designed to be sandwiched betweenone part of the peripheral inner surface and a corresponding part of thecontact surface. The purpose is to compensate for the defects offlatness and/or interruptions of the contact surface and/or overly greatdeviations of the distance which exists between the inner peripheralsurface and the indicated contact surface, according to circumstances.

The thickness of each transition element is therefore variable as afunction of the profile of the corresponding part of the contactsurface, but also as a function of the desired relative positioningbetween the glass pane and the indicated contact surface, viewedoverall. The object is to permanently connect the inner peripheralsurface on the contact surface by using a constant cement thicknesswhich is a guarantee of perfect fixing and tightness.

The invention as defined above has the advantage that it can be adaptedto a conventional motor vehicle, i.e. therefore a motor vehicle which isprimarily designed to receive a sheet metal roof. It is in fact moreeconomical to adapt glass rooves instead of modifying the contactsurface of any standard vehicle.

This invention also relates to features which arise in the course inthis description and which can be considered individually or accordingto all their possible technical combinations.

Other features and advantages of the invention will become apparent fromthe following description in which embodiments are explained withreference to the drawings.

FIG. 1 shows a view from underneath with a partial representation of atranslucent roof element as claimed in the invention;

FIG. 2 shows the roof element as shown in FIG. 1 in a cross sectionaccording to plane AA′;

FIG. 3 shows the roof element as shown in FIG. 1 in a cross sectionaccording to plane BB′; and

FIG. 4 shows one version of the invention.

For reasons of clarity the same elements were labelled with the samereference numbers. Likewise only the elements critical to theunderstanding of the invention were shown, regardless of the scale andeach time in schematic form.

FIG. 1 shows a translucent roof element 1 which is designed to close anopening 102 made in the roof 101 of a motor vehicle 100. Only onelongitudinal half is visible here, but it is clear that the roof element1 is in fact completely symmetrical with respect to the plane XX′.

As is apparent from FIGS. 2 and 3, the opening 102 is bordered by a stop104 which forms the contact surface 103 which is an integral componentof the body structure which forms the roof 101. The roof element 1 onthe one hand has a translucent pane 2 which is permanently connected (orcan be permanently connected) to the indicated contact surface 103.

In this special embodiment which is given simply as an example, thetranslucent pane 2 is made of glass. But it is obvious that any othertransparent or translucent material could be equivalently used.

According to the subject matter of this invention, the roof element 1has two transition elements 20 here which are permanently joined by acement bead 4 on the peripheral inner surface 3 of the pane 2. Eachtransition element 20 otherwise has a support surface 21 which runsessentially parallel to one part of the opposing support surface 103.The permanent connection between the support surface 21 and theindicated corresponding part of the contact surface 103 is in turnexecuted by cementing, this time via a cement bead 5.

It should be noted that the peripheral inner surface 3 is defined as anysurface which is located on the edge or on the inside 6 of the pane 2.

Each transition element 20 is thus able to compensate for anyirregularity of parallelism and/or of the distance between theperipheral inner surface 3 and the contact surface 103. Cementing canthen advantageously be done with a constant cement thickness for anoptimum connection and tightness.

In other words, each transition element 20 has an essentiallycomplementary shape to the corresponding part of the contact surface103. It therefore forms an ideal transition element for the connectionof these two elements which are almost never complementary in practice,and it should be emphasized that the regularity and continuity of cementapplication constitute criteria essential for good cementing.

In this embodiment which was selected for explanation of the invention,only the two lengthwise edges 7 of the glass pane 2 have transitionelements 20 which are otherwise completely symmetrical. The twotransverse edges forward 8 and to the rear 9 of the glass pane 2 fortheir part have no transition elements 20 at all.

As can be seen in FIG. 2, the ends of each transition element 20 areadvantageously made such that they have no interruptions with referenceto the directly adjacent parts 10 of the peripheral inner surface 3. Inthis example each of the pertinent ends have a beveled part 22 which isable to keep essentially constant the thickness of the cement bead 5which connects the transition element 20 and the contact surface 103.

According to one special feature of the invention, each transitionelement 20 has a shape which corresponds essentially to the space whichon the one hand separates the peripheral inner surface 3 and on theother the contact surface 103 which is covered with a constant andsuitable cement thickness when the relative positioning of the indicatedperipheral inner surface 3 and the indicated contact surface 103 isoptimum.

In practice, therefore any transition element 20 has a complex shapewhich results from the often complicated profile of the contact surface103. The convex part of the contact surface 103 corresponds to eachconcave part of the transition element 20 and vice versa.

According to another feature of the invention, each transition element20 has an inner surface 23 with a shape which is essentiallycomplementary to the part of the peripheral inner surface 3 to which itis connected by cementing, and an outer surface 24 which forms a supportsurface 21 with a shape which is essentially complementary to the partof the contact surface 103 to which it is likewise connected bycementing.

According to the version shown in FIG. 4, the transition between thesupport surface 6 of the cement on the glass and the support surface ofthe cement on the transition element 20 is ensured by the supportsurface 22 which is formed by fabrication of the glass/transitionelement or a molded cement between the glass and the transition element.

As is apparent from FIG. 1, each transition element 20 is provided witha plurality of projecting parts which form calibration stops 25 a, 25 b,25 c, 25 d with a height which corresponds to the desired thickness ofthe cement. The distal end of each calibration stop 25 a, 25 b, 25 c, 25d is designed to come into contact with the support surface 103. Thepresence of these projecting calibration stops 25 a, 25 b, 25 c, 25 denables positioning of the glass pane 2 connected to the transitionelements 20 with reference to the contact surface 103 with a relativelygiven distance according to the desired thickness of the cement.Preferably the indicated calibration stops 25 a, 25 b, 25 c, 25 d areregularly distributed along each transition element 20.

FIG. 1 shows likewise that in a similarly advantageous manner each freepart 11, 12 of the peripheral inner surface 3 has several calibrationstops 13 a, 13 b, 13 c; 14 a, 14 b, 14 c, 15 c with a heightcorresponding to the desired cement thickness. It should be noted thatthe free part 11, 12 is defined of course as any part of the peripheralinner surface 3 which is not provided with any transition element 20.Here again the calibration stops 13 a, 13 b, 13 c; 14 a, 14 b, 14 c, 15c are also advantageously distributed regularly along each free part 11,12.

In this embodiment each transition element 20 is made of metal. In anequivalent manner however it could also consist of plastic materialwhich can optionally have the form of a thermoplastic or duroplasticmaterial or it could also be formed by a cement bead of extrudedpolyurethane which is applied directly to the glass pane 2.

As shown in FIG. 3, the roof element 1 can be joined to a knowndarkening mechanism 30 which can be extended parallel to the insidesurface 6 of the glass pane 2 in order especially to limit thegreenhouse effect within the passenger compartment of the motor vehicle100 on days with high incident solar radiation. In this example, itseems to be especially advantageous that one or more transition elements20 are able to carry the darkening mechanism 30 and especially its guiderails 31. This feature enables direct permanent connection of thedarkening mechanism 30 to the roof element 1 and thus advantageousformation of a proper, complete module which is ready to be installed.

Of course each transition element 20 can be used to hold other parts ofthe motor vehicle 100, such as for example external trim 40 or innerlining.

1-12. (canceled)
 13. Roof element for closing an opening in a roof of amotor vehicle, comprising: a translucent pane for permanent connectionto a contact surface which borders an opening of a roof of a motorvehicle, and at least one transition element which is joined permanentlyto an inner peripheral surface of the pane and has a support surfacewhich is essentially parallel to a part of the contact surface on whichthe support surface is to be superimposed for connection of the pane tothe contact surface.
 14. Roof element as claimed in claim 13, whereineach transition element has a shape which corresponds essentially to aspace which separates the peripheral inner surface and the contactsurface when it is covered with a constant cement thickness.
 15. Roofelement as claimed in claims 13, wherein each transition element has aninner surface with a shape which is essentially complementary to part ofthe peripheral inner surface of the pane to which it is permanentlyconnected, and an outer surface which forms a support surface with ashape which is essentially complementary to the part of the contactsurface on which it is to be superimposed.
 16. Roof element as claimedin claim 13, wherein the transition between a support surface of thecement on the translucent pane and a support surface of the cement onthe transition element is ensured by a support surface which is formedby a glass/transition element or a molded cement element that isprovided between the translucent pane and the transition element. 17.Roof element as claimed in claim 16, wherein each transition element hasat least one projecting part which forms a calibration stop with aheight that corresponds to a desired thickness of the cement.
 18. Roofelement as claimed in claim 17, wherein each free part of the peripheralinner surface has at least one calibration stop with a heightcorresponding to a desired cement thickness.
 19. Roof element as claimedin claim 18, wherein the calibration stops are distributed regularlyalong the peripheral inner surface of the pane.
 20. Roof element asclaimed in claim 13, wherein each transition element has at least oneprojecting part which forms a calibration stop with a height thatcorresponds to a desired thickness of the cement.
 21. Roof element asclaimed in claim 20, wherein the calibration stops are distributedregularly along the peripheral inner surface of the pane.
 22. Roofelement as claimed in claim 13, wherein each free part of the peripheralinner surface has at least one calibration stop with a heightcorresponding to a desired cement thickness.
 23. Roof element as claimedin claim 22, wherein the calibration stops are distributed regularlyalong the peripheral inner surface of the pane.
 24. Roof element asclaimed in claim 13, wherein the at least one transition element isprovided with means for carrying a darkening mechanism for the pane. 25.Roof element as claimed in claim 13, wherein the at least one transitionelement made of metal.
 26. Roof element as claimed in claim 13, whereinthe at least one transition element is made of plastic.
 27. Roof elementas claimed in claim 13, wherein each transition element is permanentlyjoined to the pane by cementing.
 28. Roof element as claimed in claim13, wherein the pane is made of glass.
 29. Method of permanentlyattaching a translucent pane made so as to close a roof opening of amotor vehicle provided with a contact surface constructed for receivinga sheet metal roof panel, comprising the steps of: permanently joiningat least one transition element to an inner peripheral surface of thepane, the at least one the transition element having a support surfacewhich is essentially parallel to a part of a contact surface of motorvehicle on which the support surface is to be superimposed forconnection of the pane to the contact surface; and connecting the atleast one transition element to the contact surface a layer of cementhaving a constant cement thickness.
 30. The method of claim 29,comprising the further step of providing a transition between a supportsurface of cement on the translucent pane and the support surface of thecement on the transition element with a support surface which is formedby a glass/transition element or a molded cement element that isprovided between the translucent pane and the transition element.